For a thorough jitter analysis, the components of jitter such as Data Dependent Jitter (DDJ), Periodic Jitter (PJ), Other Bounded Uncorrelated Jitter (OBUJ) and Random Jitter (RJ) must be separated.
So far, techniques are known that exclusively relate on determining the Time Interval Error (TIE) of the Total Jitter (TJ). In fact, the causes of the different jitter types lead to a distortion of the received signal and they, therefore, have an influence on the TIE via the received signal. Accordingly, the respective components of jitter are calculated based one the Time Interval Error (TIE) of the Total Jitter (TJ) determined previously.
The respective components of jitter are obtained by averaging operations. For instance, the Data Dependent Jitter (DDJ) is estimated by averaging the Time Interval Error (TIE) of the Total Jitter (TJ), namely a DDJ eye diagram or a DDJ worst case eye diagram. Moreover, certain components of jitter cannot be determined in a reliable manner.
When the total jitter component and the random jitter component of a signal are known, a deterministic jitter component may be determined by calculating a deconvolution of the random jitter and the total jitter. As the respective convolution matrices usually have a determinant near zero, pseudo-inverse matrices have to be used and/or the regularization factors have to be employed. However, signal noise is highly amplified in the process yielding in a result that is very noisy.
For instance, OBUJ is a measure for the strength of cross talk between a transmission channel transmitting a data signal and other signal channels, wherein the cross talk constitutes an uncorrelated perturbation for the data signal. In the prior art, only a peak-to-peak value of the OBUJ is estimated based on a model of the OBUJ. However, for debugging a device under test, further information about the OBUJ would be desirable.
Accordingly, there is a need for a fast and reliable possibility to determine a jitter component of a data signal, particularly the Other Bounded Uncorrelated Jitter (OBUJ).